间套作种植提升农田生态系统服务功能

间套作是指在同一块土地上同时种植两种或两种以上的作物,能够充分利用有限资源,提升单位面积物质产出,同时还具有多重其他生态效益,是一种基于生物多样性的可持续农业发展范式。生态系统服务是评价生态系统功能的重要突破口,也是当前生态学领域研究的热点问题。从生态系统服务的角度论述间套作种植提升农田生态系统服务功能,并从物质产出、土壤肥力维持、生物多样性保护、水土保持、病虫草害和有害污染物控制等方面论述了间套作种植提升农田生态系统功能的实践及机制。在此基础上,构建了间套作农田生态系统服务功能评价的理论框架和指标体系,并提出了间套作种植农田生态系统未来应加强的研究方向。

Intercropping enhances the farmland ecosystem services

With the fast increase of population and global environmental changes, it is a big challenge to ensure food security with shrinking cropland and limited resources in an environment-friendly way, which can maintain or even improve soil fertility, and protect environment. Recently, highlights have been shed on the integrated and efficient utilization of different cropping strategies including intercropping, which is on the edge of being abandoned in the farming systems. Intercropping, a land-use strategy of cultivating two or more crop species in the same pieces of land at the same time, is an old and traditional cropping practice. Generally, there are two main intercropping systems, i.e., strip intercropping and relay intercropping, both of which are trying to make more efficient use of the available growth resources on the bases of the complementary utilization of growth resources by the component crops. These cropping strategies are still common practiced in the world especially in developing countries, such as China, India, Southeast Asia, Latin America, and Africa. The most common advantage of intercropping is the production of greater yield on a given piece of land by making more efficient use of the available growth resources using a mixture of crops of different rooting ability, canopy structure, height, and nutrient requirements based on the complementary utilization of growth resources by the component crops. More importantly, it also has other exclusive ecological functions, such as improving soil fertility through biological nitrogen fixation with the use of legumes, increasing soil conservation through greater ground cover than sole cropping, protecting more species by providing more habitats, and allowing lower inputs through reduced fertilizer and pesticide requirements, thus minimizing environmental impacts of agriculture, Therefore, intercropping has been considered as a paradigm of sustainable agriculture based on the complementary mechanism of different crop species. Ecosystem services, which represent the benefits of human populations derive, directly or indirectly, from ecological processes and the ecosystem function, are components of nature, directly enjoyed, consumed, or used to yield human well-being. Undoubtedly, as one of the largest and most productive ecosystems on the earth land, the cultivated lands play irreplaceable roles in providing human well-being. However, these ecosystem services are in a state of decline, which have or will result in large and negative impacts on future human welfare. How to maintain or improve ecosystem services has become a grand task both in political and academic circles. Although there is a exponentially rising researches related to ecosystems services over the past decade, however, little attention has been paid to the ecosystem services from intercropping cropland. In this paper, we highlighted the possible ecosystem services of intercropping agricultural strategy with respects of productivity, soil fertility, biodiversity conservation, soil and water conservation, pest, and disease control, and environment protection by analyzing the available related publications. We concluded that intercropping can not only improves cropland ecosystem services with respects of provisioning services, but also improves multiple ecological services, such as supporting services and regulating services, compared with sole cropping. At last, we propose a theoretical framework to evaluate the multiple ecosystem services of intercropping cropland and give evidence on how to quantify these services and functions, together with some suggestions on future researches that should be strengthened in the field of agro-ecology.